The United States is a global leader in defending the rights of people with disabilities, thanks largely to the Americans With Disabilities Act of 1990, one of President George H.W. Bush’s crowning accomplishments. Now the Senate has a chance to extend the spirit of that law — and with it, real protections for the disabled — beyond our borders. It can vote on Tuesday to ratify the United Nations Convention on the Rights of Persons With Disabilities, which declares that all citizens, regardless of ability, deserve to live in dignity, safety and equality under the law.

Signed by President Obama in 2009, the treaty has been ratified by 125 countries. The Senate Foreign Relations Committee approved it last July in a bipartisan vote, 13-6, while also passing a resolution to clarify, in case anybody was worried, that the United States would surrender none of its sovereign authority by joining the convention. The the treaty would have no power to alter or overrule United States law, and any recommendations that emerge from it would not be binding on state or federal governments or in any state or federal court.

But it would encourage other countries to bring their treatment of the disabled up to America’s gold standard, the A.D.A. That is more than enough reason to support it. A broad array of disability-rights groups say also that the treaty’s benefits for disabled Americans traveling abroad, particularly veterans, will be considerable.